Manufacture of new azo dye stuff



Patented Mar. 31, 1936 PATENT OFFIC MAN'UFACTURE OF NEW AZO DYESTUFF Mordecai Mendoza, Blackley, Manchester, England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain a No Drawing. Application January 17, 1935,-

Serial No. 2,301. In Great Britain January 6 Claims. (on. 8-5) According to, the present invention I manuiacture new azo dyestufl. of the constitution 10 by coupling tetrazotized 3:3-dimethoxy-4:4'-

diaminodiphenyl with 2 molecular proportions of 1z8-aminonaphthol-2:4-disulphonic acid in alkaline medium and then treating with a hot alkaline copper solution until the alkyl groups have been split oflf.

Also according to the invention I apply the new dyestufi having the said constitution to cellulose materials by mthods for direct dyestuifs.

In this way I obtain greenish-blue shades on cellulosic materials, which have very good fastness to light and to soap. Such a result has not previously been obtainable by means of direct dyeing dyestufis.

Although it is known to obtain direct azo dyestufis from tetrazotized-p-p'-diaminodiphenyls by coupling in alkaline solution with hydroxy compounds adapted to couple in ortho position to give deystufis which are improved in Iastness to light when after-coppered on the fibre and although it is known to prepare coppercontaining dyestufl's in substance by coupling tetrazotized dianisidine and tetrazotized 3:3'-diethoxy benzidine with naphthol or aminonaphtholsulphonic acids by treating with a hot dilute acid solution of copper sulphate (cf. British Pat ent No. 113,141) and by treating with ammoniacal copper sulphate (of. British Patent No. 395,027) it has not been known to obtain a. dyestuif giving the valuable results of this new dyestufi.

In the manufacture of the new dyestufi, I have found that complete interaction and removal of the alkyl groups only takes place in alkaline medium. I have also found that the dyestuffs obtained in the absence of complete interaction give dyeings that are defective in 'fastness to light and washing.

The invention is illustrated, but not limited, by the following examples in which the parts are by weight.

Y Example 1 90.4 parts of the dyestuff obtained by coupling the tetrazo derivative of 3:3'-dimethoxy-4:4'- diaminodiphenyl with two molecular proportions of 1:8-aminonaphthol-2:4-dlsulphonic acid in alkaline medium are dissolved in 2000 parts of SOxH SaH

hot water. There is then stirred in a mixture of JD 60 parts of aqueous ammonia (sp. gr. .880) with 50 parts of crystalline copper sulphate dissolved in 200 parts of water. The whole is stirred and boiled under a reflux condenser for about 20 hours, i. e. until methylamine ceases to be evolved.

At the end of this period, the resulting suspension is cooled to room temperature, the alkalinity is diminished by-adding about 30 parts of 36% hydrochloric acid, and 300 parts of common salt are stirred in.

The new copper complex is then filtered off,

. dried and ground. It is readily soluble in water giving a greenish-blue solution and when dyed on cotton from an alkaline bath by the usual direct dyeing process it yields green-blue shades of very good fastness to light.

Analysis shows that there is one atomic proportion of copper to each three atoms of nitrogen, i. e. there is one atom of copper to each azo group. The new copper derivative is unchanged even after prolonged boiling with dilute aqueous Example 2 Example 3 g 'A printing paste is made up as follows:--

Parts New dyestufl 0.8 Water 27.2 Glycerine 5 I Gum tragacanth thickening 8% 'Sodium phosphate 2 Patent No. 2,056,159.

0 c1 0 o--'oi --o l I a which comprises treating with a hot alkaline copper solution until the alkyl groups have been split off, the sac dyestufi made by coupling tetrazotized 3:3'-dimethoxy 4:-i'-diaminodiphenylv with 2 molecular proportions of 1:8-aminonaphthol-2z4-disulphonic acid in alkaline medium.

2. The azo dyestufl represented by the formuia 3. The process vwhich comprises coupling in alkaline medium tetrazotized 3:3'-dimethoxy- 4 :4'-diaminodipheny1 with two molecular proportions of 1:8-aminonaphthol-2z4-disnflphonic acid,

dissolving 90.4 parts of the product in water, admixing 60 parts aqueous ammonia of specific gravity .880 and parts copper sulfate in 200 parts of water, boiling under reflux for about 20 hours with stirring, cooling to room temperature, adding about 30 parts of 36% hydrochloric acid CERTIFICATE NH! i: sols and 300 parts of salt and filtering and drying .the copper containing dye. 4. The process which comprises dissolving in water the product 01' coupling-in alkaline medium tetrazotized 3:3 dimethoxy 4:4 diaminodi phenyl with two molecular proportions of 1:8- amino-naphthol-2:4-disulphonio acid, admixing ammonia and aqueous coppersulfate, refluxing until'methylamin'e no longer evolves, cooling, adding hydrochloric acidand salt, and segregating the dye.

5. The process which comprises dissolving in aqueous basic medium the product of coupling in alkaline medium tetrazotized 3:3'-dimethoxy- 4:4'-diaminodiphenyl with two molecular proportions of 1:8-aminonaphthol-2:4-disulphonic acid, admixing aqueous copper sulfate, refluxing until Ol r interaction is complete. and segregating the (We. 6. The process which comprises treating with a hot copper sulfate solution until the alkaline groups have been split off, the azo dvestufl resulting from the coupling in alkaline medium of tetrazotized 3:3 dimethoxy 4:4 diaminodiphenyl and two molecular proportions of 1:8- aminonaphthol-2z4-disulphonic acid.

MORDECAI MENDOZA.

OF CORRECTION.

. March 31, 1956.

MQRDECAI MENDOZA.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction -as follows: Page 2, second column, line 7, claim 4, for "2 :4 'i read 2:4; and that the said Letters -Pat ent should be read with this correction therein that the record of the case in the Patent Office.

Signed and sealedthis 30th day of June, A. D. 1936.

I (S sal) v Henry Van Arsdalo Acting Commissioner of Patents.

the same may conform to Patent No. 2,056,159.

0 c1 0 o--'oi --o l I a which comprises treating with a hot alkaline copper solution until the alkyl groups have been split off, the sac dyestufi made by coupling tetrazotized 3:3'-dimethoxy 4:-i'-diaminodiphenylv with 2 molecular proportions of 1:8-aminonaphthol-2z4-disulphonic acid in alkaline medium.

2. The azo dyestufl represented by the formuia 3. The process vwhich comprises coupling in alkaline medium tetrazotized 3:3'-dimethoxy- 4 :4'-diaminodipheny1 with two molecular proportions of 1:8-aminonaphthol-2z4-disnflphonic acid,

dissolving 90.4 parts of the product in water, admixing 60 parts aqueous ammonia of specific gravity .880 and parts copper sulfate in 200 parts of water, boiling under reflux for about 20 hours with stirring, cooling to room temperature, adding about 30 parts of 36% hydrochloric acid CERTIFICATE NH! i: sols and 300 parts of salt and filtering and drying .the copper containing dye. 4. The process which comprises dissolving in water the product 01' coupling-in alkaline medium tetrazotized 3:3 dimethoxy 4:4 diaminodi phenyl with two molecular proportions of 1:8- amino-naphthol-2:4-disulphonio acid, admixing ammonia and aqueous coppersulfate, refluxing until'methylamin'e no longer evolves, cooling, adding hydrochloric acidand salt, and segregating the dye.

5. The process which comprises dissolving in aqueous basic medium the product of coupling in alkaline medium tetrazotized 3:3'-dimethoxy- 4:4'-diaminodiphenyl with two molecular proportions of 1:8-aminonaphthol-2:4-disulphonic acid, admixing aqueous copper sulfate, refluxing until Ol r interaction is complete. and segregating the (We. 6. The process which comprises treating with a hot copper sulfate solution until the alkaline groups have been split off, the azo dvestufl resulting from the coupling in alkaline medium of tetrazotized 3:3 dimethoxy 4:4 diaminodiphenyl and two molecular proportions of 1:8- aminonaphthol-2z4-disulphonic acid.

MORDECAI MENDOZA.

OF CORRECTION.

. March 31, 1956.

MQRDECAI MENDOZA.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction -as follows: Page 2, second column, line 7, claim 4, for "2 :4 'i read 2:4; and that the said Letters -Pat ent should be read with this correction therein that the record of the case in the Patent Office.

Signed and sealedthis 30th day of June, A. D. 1936.

I (S sal) v Henry Van Arsdalo Acting Commissioner of Patents.

the same may conform to 

